[pci] about turnaround

[sumnow <sumnow@263.net>]

hi all,

dose turnaround cycle mean that if one signal is in turnaround cycle, no device will enable its OE and drives it on PCI bus.

for instance, in a basic read transaction, after a master drives address on AD , it will enter a turn around cycle. then the master will disable AD OE and stop driving AD. at this cycle, there is no device driving AD. one or two cycle later target will drive data on DATA.

if i am right, who is responsible for keeping signal stable on PCI bus during turnaround cycle? 

i think since the bus is normally driven most of the time, the precharged bus will retain its state for some time. but if it is right, how long the state can be retained.

i really appreciate the help for clarifying the mind.

sumnow



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